From f522589c139debb8af56dbead0c6e9dfca2d5ce4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Fri, 6 Dec 2024 18:28:38 +0100 Subject: iio: adc: ad_sigma_delta: Fix a race condition MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The ad_sigma_delta driver helper uses irq_disable_nosync(). With that one it is possible that the irq handler still runs after the irq_disable_nosync() function call returns. Also to properly synchronize irq disabling in the different threads proper locking is needed and because it's unclear if the irq handler's irq_disable_nosync() call comes first or the one in the enabler's error path, all code locations that disable the irq must check for .irq_dis first to ensure there is exactly one disable call per enable call. So add a spinlock to the struct ad_sigma_delta and use it to synchronize irq enabling and disabling. Also only act in the irq handler if the irq is still enabled. Fixes: af3008485ea0 ("iio:adc: Add common code for ADI Sigma Delta devices") Signed-off-by: Uwe Kleine-König Link: https://patch.msgid.link/9e6def47e2e773e0e15b7a2c29d22629b53d91b1.1733504533.git.u.kleine-koenig@baylibre.com Signed-off-by: Jonathan Cameron --- include/linux/iio/adc/ad_sigma_delta.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/iio/adc/ad_sigma_delta.h b/include/linux/iio/adc/ad_sigma_delta.h index 895b7ebf4be5..200130e4244d 100644 --- a/include/linux/iio/adc/ad_sigma_delta.h +++ b/include/linux/iio/adc/ad_sigma_delta.h @@ -86,6 +86,7 @@ struct ad_sigma_delta { /* private: */ struct completion completion; + spinlock_t irq_lock; /* protects .irq_dis and irq en/disable state */ bool irq_dis; bool bus_locked; -- cgit v1.2.3